There's a twitter user whom I can't recall the name of that makes high quality UE4 maps of older Kingdom Hearts settings, like Traverse Town. Imagine running around there in KH3, hearing Hand in Hand all over again. Imagine instant Keyblade switching, no more half second of lag when you want to switch your weapon mid-combo, now you can be as stylish and improvisational as you want without dropping your combo. Imagine the character mods, be it playable, boss, or team. Sulley vs Vanitas. Going through the game as KH2 Sora. Drive forms in cutscenes. Relocating Data Battles to unique arenas. Modded Keyblades. Day/Night mods for different worlds.
If your head isn't spinning with the possibilities, who are you?
Are you thinking of Caleb? He’s amazing and talented.
We can move Disney characters out of their worlds and have them in parties, making the game a real Disney crossover. Big Hero 6 can actually be party members altogether.
People are going to mod in Spider-Man for the hell of it. Model from FF8 Remastered can be added straight into KH1/KH2. Dissidia model rips right into all of the older KH games, too...
People are going to make their own super critical mode hack that’ll be like Dark Souls.